Auxiliary feed mechanism for a sewing machine



Dec. 3, 1968 R. J. BOSER 3,413,943

AUXILIARY FEED MECHANISM FOR A SEWING MACHINE Filed Nov. 9, 1966 2 Sheets-Sheet 1 F/GJ INVENTOR. AO/VALD J. BOSE]? Dec. 3, 1968 I R. J. BOSER 3,413,943

AUXILIARY FEED MECHANISM FOR A SEWING MACHINE Filed Nov. 9, 1966 2 Sheets-Sheet 2 IN VEN TOR. AO/V/M 0 J B OSER Mam United States Patent 3,413,943 AUXILIARY FEED MECHANISM FOR A SEWING MACHINE Ronald J. Boser, 21 Bolan Drive, Huntington Station, N.Y. 11746 Filed Nov. 9, 1966, Ser. No. 593,152 6 Claims. (Cl. 112---214) The present invention relates generally to improvements for sewing machines, and more particularly to an improved auxiliary feed mechanism for a sewing machine.

Auxiliary feed mechanisms for sewing machines are well known and may take the form as shown in the patents issued to R. W. Winberg, US. Patents No. 2,777,409 and No. 3,018,746, issued respectively on January 15, 195.7, and January 30, 1962. The auxiliary feed mechanisms of these patents employ a flexible coupling connected between the motor of the sewing machine and one or more rollers which engage the material being sewn and supplement the feed movement of the feed dogs for the sewing machine. As a consequence, these auxiliary feed mechanisms minimize the production of uneven or puckered seams during sewing.

In presently known embodiments of auxiliary feed mechanisms it is desirable to incorporate the same as a part of the sewing machine in such manner as to avoid interfering with the operation and functioning of the usual elements of a sewing machine. In particular, the feed mechanism must be coordinated with the operation and functioning of the usual presser foot of the sewing machine since both these elements must engage the material during sewing operation on the machine and yet must be readily disengaged from the material in order to facilitate removal of the material following a typical sewing interval. It is therefore usual and characteristic of prior art auxiliary feed mechanisms to have the driving members thereof mounted on the presser foot so that these driving members are disengaged from the material simultaneously with the disengagement of the presser foot from the material being sewn. However, one of the essential contributions of the present invention is the recognition that during high speed sewing operation, the presser foot has a characteristic vibrating motion which in said prior art combined presser foot and auxiliary feed mechanism structures is transmitted to the driving members of the feed mechanism. This vibrating motion adversely affects the operation of the driving members because it results in a disruption in the driving contact of these members with the material being sewn.

Broadly, it is an object of the present invention to provide an improved auxiliary feed mechanism overcoming the foregoing and other shortcomings of the prior art. Specifically, it is an object to provide a feed mechanism having driving members supported on and movable with the presser foot of the sewing machine during the time the presser foot is moved from its operative position to a clearance position with respect to the material being sewn and further having means for dampening the vibration of the presser foot during sewing operation of the sewing machine.

A further object of the present invention is to provide a presser foot and auxiliary feed mechanism which are pivotally movable in unison from their operative position into a clearance position and which, during sewing operation of the machine, are independently movable relative to each other so that the transmission of vibration of the presser foot to the feed mechanism is minimized.

An auxiliary feed mechanism demonstrating objects and advantages of the present invention includes a lower and an upper first and second rotary drive means, respectively, cooperating with each other and effective to feed material interposed therebetween along a feed path past the sewing needle of the sewing machine. The upper or second rotary drive means is journalled for rotation on an end of a support bracket which at its opposite end is pivotally movable, in unison with the presser foot, about a vertical axis. Thus, both the presser foot and the upper rotary drive means are movable in a swinging motion from their operative position into a clearance position to readily permit removal of the material being sewn after a typical sewing interval. Additionally, the support bracket of the upper rotary drive means is mounted for pivotal movement about a transverse axis with respect to the presser foot and has a compression spring interposed therebetween such that vibration movement of the presser foot is dampened by the spring and is thus not transmitted to the upper rotary drive means.

The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a sewing machine having an auxiliary feed mechanism according to the present invention;

FIG. 2 is a partial elevational view, on an enlarged scale, showing details of the auxiliary feed mechanism;

FIG. 3 is a partial elevational view, in section taken on line 33 of FIG. 2, showing further details of construction of the auxiliary feed mechanism; and

FIG. 4 is an enlarged partial elevational view, in section taken on line 4-4 of FIG. 2, showing details of the driving rollers of the auxiliary feed mechanism.

Reference is now made to the drawings wherein there is shown a conventional, but somewhat simplified, high speed overseamer sewing machine 10, on which a pivotally mounted housing cover 11 is illustrated in its open position to better show structural details. The machine 10 includes a feed mechanism, generally designated 12, incorporated as auxiliary equipment therefor and powered by the sewing machine motor or drive. The incorporation of the feed mechanism 12 as part of the sewing machine 10 is achieved without adversely affecting the operation of the usual elements of the machine, particularly that of the presser foot, and yet the feed mechanism, when necessary, operates independently of these elements to provide improved feed of the material being sewn.

As is generally understood, the usual drive for the sewing machine 10 is contained within an appropriate housing 14 which is operatively connected to a stitching mechanism, generally designated 16. As best shown in FIG. 2, the stitching mechanism 16 includes needle holders 18 and associated sewing needles 20. In a Well understood manner, the sewing machine drive is effective to drive the stitching mechanism 16 such that the needles 20 are actuated through stitch-forming movements and are therefore effective in sewing material M. As is further generally understood, the sewing machine 10 includes a feed dog 22 which is driven through a movement cycle which is effective to advance the material M in a feed path P past the sewing needles 20. Assisting in this sewing operation is a usual presser foot 24 which maintains the material M in contact with the feed dog 22 during the forward stroke of the feed dog when it extends slightly above a throat plate 26 through plural feed slots 28. During this forward-movement portion of the stroke of the feed dog 22 it is inevitable that the presser foot 24 Will be slightly raised in position. Thereafter, the feed dog 22 lowers and returns to the starting point of its forward motion and thus the presser foot 24 is correspond ingly lowered in position. This is significant since the effect of this slight change in position of the presser 3 foot 24, particularly during high speed operation of the sewing machine 10, provides a vibratory motion to the presser foot 24.

In accordance with the present invention, the sewing machine is provided with the auxiliary feed mechanism 12 which supplements the feed action of the feed dog 22. It is desirable that the feed mechanism 12, like the presser foot 24, be readily moved from an operative position in which it is engaged with the material M being sewn to a Clearance position with respect thereto so that after a sewing interval the material M can readily be removed from the sewing machine 10. However, an essential contribution of the present invention is the recognition that, during sewing, the presser foot 24 has the foregoing characteristic vibratory motion which it is not desirable to transmit to the feed mechanism 12. Thus, although it is desirable that the feed mechanism 12 move in unison with the presser foot 24 during movement thereof from an operative position in contact with the material M into a clearance position with respect to the material M, it is not desirable that the characteristic vibratory motion of the presser foot 24 be transmitted to the feed mechanism 12.

To the above end, the feed mechanism 12, which is most clearly shown in FIGS. 24 and to which reference is now made, includes means mounting the presser foot 24 for swinging movement about a vertical axis. More particularly, located rearwardly on the sewing machine 10 is a support 30 pivotally mounted as at 31 and having a horizontal leg 30a. The presser foot 24 is appropriately connected at one end, as at 32, to a support bracket 34 which at its other end terminates in a pair of laterally extending ears 34a, 34b. The ears 34a, 34]) are disposed about the horizontal leg 30a and a first pivotal connection, generally designated 36, is formed therebetween by the bolt and nut 38 and 40, the vertical axis of the pivotal connection 36 being the threaded body of the bolt 38.

Reference is now made to a spring-biasing mechanism 44 for the presser foot 24. As is clearly seen in FIG. 1, to which reference should be made in conjunction with FIGS. 24, there is an arm 42 extending laterally of the housing 10 which at its free end has a vertical through bore which serves as a housing for the spring-biasing mechanism 44. The mechanism 44 includes a rod 46 which is under a downward bias imposed by the spring 48, the lower end of the rod 46 having a notch 50 therein by which the spring-biasing mechanism 44 is detachably connectable to the presser foot support bracket or body 34. Thus, in the operative position of the presser foot 24 the notch 50 is engaged with the presser foot body 34 such that a downward bias is exerted on the presser foot 24 to maintain this element in contact with the material M which is being sewn to insure that the material M is properly fed along the feed path P during forward movement of the feed dog 22. However, merely by lifting the rod 46 of the spring-biasing mechanism 44 the presser foot body 34 is freed of its connection therewith and thus can partake of swinging movement about the pivotal connection 36. This procedure is followed at the end of a stitching interval when it is necessary to move the presser foot 24 in the direction of the arrow A from its operative position as shown in FIG. 2 into a clearance position (not shown) to facilitate removal of the material M from the sewing machine 10.

The operable elements of the feed mechanism 12 which are effective in imparting feed movement to the material M include a first rotary drive means 52 located at the same level as the throat plate 26 at a position rearwardly of the sewing needle 20 and along the feed path P. The first rotary drive means 52 includes a yoke 54 having bifur cated extensions 54a thereon on which a roller 56 with a roughened material-contacting surface 56a is appropriately joumalled for rotation. Roller 56 includes a shaft extension 58 which is operatively connected, as by a key or the like, to a flexible coupling 60 which at its opposite end (not shown) is connected to the motor of the sewing machine 10 such that a torsional moment is developed in the flexible coupling 60 and results in the roller 56 being selectively powered in rotation. This is described in detail in U .8. Patent No. 2,777,409 issued on Jan. 15, 1957 to R. W. Winberg and is a well understood phenomenon which need not be repeated herein. It will sufl'lce to note that the torsional moment of the flexible coupling 60 is eifective to drive the roller 56 in rotation whenever the feed dog 22 is moving through its forward stroke along the feed path P.

Cooperating with the roller 56 is a second roller 62 which forms an integral part of a second rotary drive means, generally designated 61, and which completes the feed meohanism 12. Roller 62 also is provided with a roughened peripheral surface 62a which makes contact with the material M and is journalled for rotation between bifurcated arms 64a of a support bracket 64. Further, roller 62 has an axial shaft 66 which is operatively connected by appropirate coupling means, as at 68 as best shown in FIG. 4, to a flexible coupling 70 which is efifective to power the roller 62 in rotation during feed movement of the feed dog 22. Thus, both flexible couplings 60 and 70 function in a similar manner. The flexible coupling 70 for the roller 62 is, of course, consistent with and enables unrestricted swinging of the roller support bracket 64 between its operative and clearance positions.

The support bracket 64 for the roller 22 extends from its connection to the roller 62 rearwardly from the location where sewing is taking place and has an L-shaped plate portion 64a which is supported along an edge of the rear portion of the presser foot body 34. The plate 64a is connected to the presser foot body 34 by a second pivotal connection 72. As best shown in FIG. 3, the pivotal connection 72 is formed by a bolt 74 disposed through a slightly oversized bore in one leg of the plate 64a and threadably engaged in a laterally oriented threaded bore in the presser foot body 34. Thus, the pivot axis of the pivotal connection 72 coincides with the axis of the body of the bolt 74 and permits independent movement of the presser foot body 34 and the support bracket 64 relative to each other about the horizontally oriented axis of the pivotal connection 72.

Completing the mounting for the support bracket 64 is a biasing arrangement, generally designated 76, for the roller 62 mounted on this bracket. The arrangement 76 includes an upstanding threaded element 78 on the presser foot body 34 which extends through an oversized hole 80 in the support bracket plate 64a. A compression spring 82 is disposed about the element 78 and is seated at one end against a nut and washer arrangement 84, 86 on the element 78, and at its other end against a washer 88 slidably disposed on the element 78 and resting on the support bracket plate 64a. In this manner the support bracket 64 is biased under the urgency of the compression spring 82 downwardly such that the roller 62 is held in contact with the material M being sewn. A conventional threaded element 90 is threadably adjustable at the forward edge of the plate 64a and thus functions as a positive stop limiting the downward movement of the support bracket 64. Additionally, by virtue of the interposed position of the compression spring 82 between the presser foot body 34 and the support bracket 64 and the independent movement of these elements with respect to the transverse axis of the second pivotal connection 72, the compression spring 82 is effective in dampening any vibration movement in the presser foot 24 before it can be transmitted to the support bracket 64. As a consequence, during high speed sewing operation of the sewing machine 10 the roller 62 does not vibrate and is therefore maintained continuously in contact with the material M. The roller 62 is therefore effective in supplementing the feed movement of the material M each time that the feed dog 22 moves through that portion of its cycle of movement along the feed path P. Thus, the rollers 56, 62 provide positive intermittent feed movement of the material M which minimizes stitch pucker and the like during sewing.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.

What is claimed is:

1. An auxiliary feed mechanism for a sewing machine of the type including a sewing mechanism, a sewing needle operatively connected to and adapted to be reciprocated through stitch-forming movement by said sewing mechanism, a feed dog drive operative to feed material along 'a feed path past said sewing needle, a support located rearwardly of said sewing needle, a presser foot, and a first pivotal connection mounting said presser foot to said support such that said presser foot extends into an operative position relative to said feed dog drive to engage material fed therebetween and is swingable about said first pivotal connection from said operative position into a clearance position, said auxiliary feed mechanism comprising a first rotary drive means including a materialcontacting surface located rearwardly of said sewing needle along said material feed path adapted to advance material along said feed path, a second rotary drive means including a material-contacting surface mounted for swinging movement in unison with said presser foot having a cooperating operative position with said first rotary drive means such that said material-contacting surfaces thereon engage opposite sides of material fed therebetween, and an elongated support bracket for said second rotary drive means, said support bracket having means at one end for journalling said second rotary drive means for rotation thereat and having at its opposite end a second pivotal connection to said presser foot oriented transversely to said first pivotal connection such that said support bracket and said presser foot are movable independently of each other in a vertical plane to thereby minimize the transmission of vibration movement of said presser foot to said support bracket.

2. An auxiliary feed mechanism as defined in claim 1 including a compression spring and means supporting said compression spring including seat means formed on said presser foot for one end of said compression spring and a surface on said support bracket adapted to be contacted by the opposite end of said spring such that said spring is effective to bias said support bracket and said secondary rotary drive means thereon downwardly into contact with said material being sewn and simultaneously to dampen any vibration movement of said presser foot.

3. An auxiliary feed mechanism for a sewing machine as defined in claim 2 including a spring-biasing mechanism detachably connectable to said presser foot having an operative position of connection to said presser foot for urging said presser foot against said material being sewn and adapted to be detached therefrom to permit swinging movement of said presser foot into said clearance position thereof.

4. An auxiliary feed mechanism for a sewing machine as defined in claim 2 wherein said second rotary drive means includes a flexible drive shaft, said flexible drive shaft being operatively connected to transmit rotary power of said sewing machine to said drive means While permitting swinging movement of said drive means in unison with said presser foot.

5. An auxiliary feed mechanism for a sewing machine of the type including a sewing mechanism, a sewing needle operatively connected to and adapted to be reciprocated through stitch-forming movement by said sewing mechanism, a feed dog drive operative to feed material along a feed path past said sewing needle, a support located rearwardly of said sewing needle, a presser foot, and a first pivotal connection mounting said presser foot to said support such that said presser foot extends into an operative position relative to said feed dog drive to engage material fed therebetween and is swingable about said first pivotal connection from said operative position into a clearance position, said auxiliary feed mechanism comprising a first driven roller having a peripheral material-contacting surface thereon located rearwardly of said sewing needle along said material feed path adapted to advance material along said feed path, a second driven roller having a peripheral material-contacting surface thereon mounted for swinging movement in unison with said presser foot and having a cooperating operative position with said first driven roller such that said materialcontacting surfaces thereon engage opposite sides of material fed therebetween, an elongated support bracket for said second driven roller, said support bracket having means at one end for journalling said second driven roller for rotation thereat and having at its opposite end a second pivotal connection to said presser foot oriented transversely to said first pivotal connection such that said support bracket and said presser foot are movable independently of each other in a vertical plane, and a spring interposed between said support bracket and said presser foot to dampen any vibration movement of said presser foot to thereby minimize the transmission of said vibration movement to said support bracket.

6. An auxiliary feed mechanism for a sewing machine as defined in claim 5 including a flexible drive shaft operatively connected to said second driven roller, said flexible drive shaft being adapted to transmit rotary power to said second driven roller while permitting swinging movement of said elongated support bracket for said second driven roller.

References Cited UNITED STATES PATENTS 3,162,157 12/1964 Chinnichi 112-211 X RICHARD J. SCANLAN, JR., Primary Examiner. 

1. AN AUXILIARY FEED MECHANISM FOR A SEWING MACHINE OF THE TYPE INCLUDING A SEWING MECHANISM, A SEWING NEEDLE OPERATIVELY CONNECTED TO AND ADAPTED TO BE RECIPROCATED THROUGH STITCH-FORMING MOVEMENT BY SAID SEWING MECHANISM, A FEED DOG DRIVE OPERATIVE TO FEED MATERIAL ALONG A FEED PATH PAST SAID SEWING NEEDLE, A SUPPORT LOCATED REARWARDLY OF SAID SEWING NEEDLE, A SUPPORT AND A FIRST PIVOTAL CONNECTION MOUNTING SAID PRESSER FOOT TO SAID SUPPORT SUCH THAT SAID PRESSER FOOT EXTENDS INTO AN OPERATIVE POSITION RELATIVE TO SAID FEED DOG DRIVE TO ENGAGE MATERIAL FED THEREBETWEEN AND IS SWINGABLE ABOUT SAID FIRST PIVOTAL CONNECTION FROM SAID OPERATIVE POSITION INTO A CLEARANCE POSITION, SAID AUXILIARY FEED MECHANISM COMPRISING A FIRST ROTARY DRIVE MEANS INCLUDING A MATERIALCONTACTING SURFACE LOCATED REARWARDLY OF SAID SEWING NEEDLE ALONG SAID MATERIAL FEED PATH ADAPTED TO ADVANCE MATERIAL ALONG SAID FEED PATH, A SECOND ROTARY DRIVE MEANS INCLUDING A MATERIAL-CONTACTING SURFACE MOUNTED FOR 